There is a heat source system using a plurality of turbo chillers. The heat source system controls the number of turbo chillers to be activated in accordance with the amount of heat required for an external load. In the number control, it is required to save energy by operating the activated turbo chillers at high efficiency.
Patent Citation 1 discloses a technology for obtaining the relationship between the coefficient of performance and the load factor of an inverter-driven turbo chiller, the coefficient of performance determined by the temperature of cooling water supplied to a condenser, and controlling the inverter in such a way that the coefficient of performance is greater than or equal to a predetermined value.
Patent Citation 1: Japanese Unexamined Patent Application, Publication No. 2005-114295